Synthesis of high energy phosphates during cold ischemic rat liver preservation with gaseous oxygen insufflation

The depletion of biochemical energy stores during anoxic ischemic preservation is a major problem affecting the viability of the graft in transplantation medicine. After cessation of blood flow and, thus, lack of metabolic substrates and oxygen supply, a swift decrease of energy-rich phosphates can be observed in the tissue, since endergonic metabolic processes continue, but no further oxidative regeneration of biochemical energy stores will take place. We investigated the effect of a continuous gaseous oxygen supply via the venous vessels during extended ischemic preservation of rat livers in University of Wisconsin preservation solution for 48 hr. Results showed that aerobic ischemic storage not only prevented the depletion of biochemical energy stores, but promoted a de novo synthesis of high energy phosphates, and significantly enhanced the functional recovery of the organs after postischemic reperfusion. The findings suggest that maintenance of oxidative energy metabolism largely protects the organ during ischemia and may enable organ viability even after extended preservation times.